Diagnostic systems may include a data retrieval device to record data from electronic control units, such as an engine control module in a vehicle. Enabling these devices often requires manual intervention, such as a person pressing a button, or receiving an electrical trigger signal from the electronic control unit. Once enabled, the diagnostic system can only begin receiving data from the electronic control unit after performing a boot sequence. However, while the diagnostic system is performing the boot sequence, the electronic control unit may begin to output valuable start-up information. Therefore, the start-up information is unknown to the diagnostic system.
Accordingly, a diagnostic system that is able to receive start-up information from the electronic control unit is needed. Specifically, a diagnostic system is needed having a wake-up circuit to enable the diagnostic system before the electronic control unit outputs valuable start-up information.
Generally, like components are numbered the same in each figure, such that the same number on multiple figures represents the same type of component although the specific implementation may be different.